With the rapid progress of URT, URT lines are being built rapidly and networked. As the need for URT operation capacity increases, usage and equipment maintenance for the signal system also increase. It is desired to reduce the number of trackside equipment and minimize the operation interval while securing safety of trains.
In a conventional URT signal system, ground equipment serves as the core for operation of trains. There are numerous kinds of ground equipment. Operation of a train is controlled in a train-ground-train manner, where the train has to perform back and forth communications with the ground equipment, leading to a long turnaround period as well as a limited flexibility and intelligent level of the control. In view of the defects in the conventional URT signal system, Communication Based Train Control (CBTC) based on vehicle-vehicle communications has been developed, which greatly simplifies the ground equipment. CBTC, with an Intelligent Vehicle On-board Controller (IVOC) mounted on the train as its core, is based on direct communications among trains. The train autonomously calculates a train movement authority based on an operation plan, railway resources, and an operation status of its own, to ensure an autonomous and safe control of the train on the railway, resulting in an improved operation efficiency and reliability of the train.
Trains should be operated with high safety and high operation efficiency. If there is a faulty train on the main line, e.g. a train with a communication fault or in an instable operation, the faulty train needs to be timely transferred by returning to a station or being moved to a turnout. Conventionally a faulty train is mainly discovered and transferred manually, where a staff needs to monitor the information from the IVOC of the train and from trackside equipment to determine if the train is faulty, and then inform a rescue train to go to the corresponding zone to transfer the faulty train. In this manner, it is necessary to provide a dedicated rescue train and so that scheduling staff may transfer the faulty train using the rescue train. This may greatly affect the trains normally operated on the main line and result in a low operation efficiency.
In addition, in conventional operation and control schemes of trains, all the operating trains share the same operation and control rule. However in some special scenarios, for example during rush hours, there is a large number of passengers in one direction of the line while only a small number of passengers in the other direction. Using the same operation and control rule for the trains in both directions will lead to a low efficiency of train control and usage of communication resources for the direction in which there is only the small number of passengers.